进程池与线程池（concurrent.futures）

from concurrent.futures import ProcessPoolExecutor
import os,time,random
def task(n):
    print('%s is running'%os.getpid())
    time.sleep(random.randint(1,2))
    return n**2
if __name__ == '__main__':
    p = ProcessPoolExecutor()     #默认开启四个进程池
    l = []
    start = time.time()
    for i in range(10):
        obj = p.submit(task,i)
        l.append(obj)
    p.shutdown()
    print('='*30)
    print([obj for obj in l])
    print(time.time() - start)

from concurrent.futures import ThreadPoolExecutor
import threading
import os,time,random
def task(n):
    print('%s:%s is running'%(threading.currentThread().getName(),os.getpid()))
    time.sleep(random.randint(1,2))
    return n**2
if __name__ == '__main__':
    t = ThreadPoolExecutor()
    l = []
    start = time.time()
    for i in range(10):
        obj = t.submit(task,i)
        l.append(obj)
    t.shutdown()
    print('='*30)
    print([obj.result() for obj in l])   #可以获取结果
    print(time.time() - start)

from concurrent.futures import ProcessPoolExecutor
import os,time,random
def task(n):
    print('%s is running'%os.getpid())
    time.sleep(1)
    return n**2
if __name__ == '__main__':
    p = ProcessPoolExecutor()
    start = time.time()
    for i in range(10):
        res = p.submit(task,i).result()    #同步执行，速度较慢，一个等一个
        print(res)
    print('='*30)
    print(time.time() - start)